Prediabetes Symptoms and Diagnosis

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

What is prediabetes?

About 41 million Americans between the ages of 40 and 74
have "prediabetes." Prediabetes is a condition that can be considered an early,
yet potentially reversible stage of the development of
type 2 diabetes. Prediabetes
is sometimes called impaired glucose tolerance or impaired fasting glucose (IGT/IFG),
depending upon the test that yielded the abnormal result. In prediabetes, a person's blood sugar (glucose) levels are
slightly higher than the normal range, but not high enough for a true diagnosis of diabetes.
People with prediabetes have a significant risk of developing full-blown
diabetes. In the Diabetes Prevention Program study, about 11% of
people with prediabetes developed type II diabetes each year during the
three year follow-up time of the study. Importantly, people with prediabetes
generally have no symptoms of the condition.

Testing for Pre Diabetes

Doctors generally use one of two different blood tests to
diagnose diabetes and prediabetes. One is called the
fasting plasma glucose test (FPG) in which
a person's blood glucose level is measured first thing in the morning before
breakfast. The normal fasting blood glucose level is below 100 mg/dl. A person
with prediabetes has a fasting blood glucose level between 100 and 125 mg/dl.
If the fasting blood glucose level is to 126 mg/dl or above, a person is considered
to have diabetes.

The second test used in the diagnosis of diabetes is the oral
glucose
tolerance test (OGTT), although this test is no longer commonly used as in
the past. This test may be used to diagnose
gestational diabetes in
pregnant women. In this test, a person's blood glucose is measured in the
morning after fasting overnight and again two hours after drinking a glucose-rich
beverage. The normal value for blood glucose is below 140 mg/dl two hours after
the drink. In prediabetes, the two-hour blood glucose is 140 to 199 mg/dl. If
the two-hour blood glucose rises to 200 mg/dl or above, a person has diabetes.

The A1c test, or
hemoglobin A1c level, is another blood test that measures how much glucose has been sticking to hemoglobin during the past
three to four months. Hemoglobin is the substance in the red blood cells that carries oxygen to the cells of the body. The A1C test is important in diabetes and prediabetes as a measure of the glucose control during the prior
three months. Normal values for the hemoglobin A1c are 5.6% or below. Values between 5.7% and 6.4% are considered to reflect prediabetes, while values of 6.5% and over are typical for diabetes.

Long-term effects of diabetes and prediabetes

Research has shown that some of the long-term effects of
diabetes on the body, such as damage to the heart and blood vessels, can begin even when a
person only has prediabetes. Having prediabetes increases your risk of
developing cardiovascular disease by about 50% compared to people with normal
blood sugar levels.

You won't necessarily know if you have prediabetes,
since the condition usually causes no specific symptoms. If you are overweight
or have other risk factors for the development of diabetes, your doctor can help
you decide if screening for
prediabetes is appropriate.

The good news for people with prediabetes is that they
can prevent or delay the development of diabetes with lifestyle modifications.
Modest weight loss through
diet and moderate exercise
(such as walking
30 minutes per day, five times a week) can slow the development of diabetes and
can even return blood glucose levels to normal in some people with prediabetes.
Overweight people who have prediabetes need not achieve their ideal body weight
to improve their condition. Studies show that a weight reduction of just 5% to
10% of body weight can improve blood glucose levels. Since you can take
measures to reverse the condition, recognition of pre-diabetes is an important
step in disease prevention.